Creating UBLinux

Editing the Boot Disk

In order to have the CDs bootable, we need to have a boot disk image.

To edit the Boot Disk, we had to get a hold of bootdisk.img from the RHEL WS 3 CD. If you followed the previous section, the bootdisk.img should be located in /home/ublinux. Otherwise, you can grab it from RHEL CD1 in images/bootdisk.img.

There are probably other (and possibly better) ways to do this, however this is how we did it for UBLinux 3.0.

To get started, we need to write the bootdisk image to a blank floppy so that you can modify it:

dd if=/home/ublinux/bootdisk.img of=/dev/fd0 bs=1024

Now you can mount the floppy disk and modify the contents of it. We modified the syslinux.cfg file so that the default option was a ResNet/DHCP network configuration kickstart file, and we also added an option for an install not pre-configured for netw
ork use. For information on creating the kickstart files, see "Creating the Kickstart".

We also modified the various message files to reflect UB specific information. Finally, we modified the splash.lss file so that we have a nice pretty UB graphic in place of the RedHat graphic.

The graphic is in a somewhat odd format, called LSS16. As the name indicates, it is limited to 16 colors. To edit the graphic, first convert it to a PPM:

lss16toppm < splash.lss > splash.ppm

Next, edit the file using The Gimp. Save the resulting file as an indexed gif with no more than 14 colors (plus black and white, for a total of 16). Then, convert the file to a pnm/ppm:

giftopnm < splash.gif > splash.ppm

Before taking the next step and converting the ppm file to an LSS, ensure that the LANG environment variable is set to en_US. RedHat 9's default LANG variable is en_US.UTF-8, which will cause the LSS conversion to fail. To actually convert the ppm to a
n lss, use this command:

ppmtolss16 < splash.ppm > splash.lss

A note on the .msg files on the floppy: These are the message files displayed when the appropriate key (as indicated in the syslinux.cfg file) is pressed. The color codes in these files refer to the index of the graphic contained in splash.lss.

After you have modified the files to your liking, we copy the image over to its proper place on disc 1 by creating another floppy image: